The present invention relates generally to jet-powered sport boats designed for use by a single person and, more particularly, to component accessories for such boats which improve their safety, stability and maneuverability.
Jet-powered watercraft have become increasingly popular over the years due in part to their maneuverability and the sensation of freedom they impart to their users. The typical jet-powered watercraft includes a water jet power assembly mounted in the hull of the watercraft. The power assembly includes an impeller or the like which propels a water stream from the nozzle of the engine to propel the craft. The nozzle is pivoted and laterally movable via linkage connected to handlebars on the watercraft enabling the operator to laterally direct the water jet stream and thereby the direction of thrust. This enables the operator to alter the direction of movement of the watercraft by rotation of the handlebars. Thus, the water jet stream serves to both propel the watercraft as well steer the watercraft.
The popularity of such watercraft has increased despite the hazards and dangers such watercraft present to the users as well as others nearby. The primary danger such watercraft present is because of the limitation that steering capability is provided solely by the jet stream from the engine. Alteration of the direction of the jet stream flow from the watercraft is provided by means of appropriate steering linkage connected to the engine nozzle. However, when the engine is off, there is no steering capability for the watercraft. Thus, when the user is coasting in to shore in order to dock the boat and thus in shallow water where swimmers are likely present, the user has no effective means of deftly steering the boat away from the swimmers. Collisions with swimmers under these circumstances are not uncommon resulting in such watercraft being banned from many beaches. In addition, engine failure or malfunction can result in complete loss of steering capability resulting in collisions with swimmers, other watercraft, docks, breakwaters, etc. with potentially disastrous results.
The handlebars of jet skis typically have a spring biased throttle control so that in the event the user falls off the vehicle the engine speed reduces to idle terminating propulsion provided to the vehicle allowing the vehicle to glide to a stop. The handlebars also typically include an electric on-off switch enabling the engine to be turned on and off quickly and easily.
When operating any type of conventional vehicle whether a personal watercraft, automobile, truck etc., a typical reaction to an impending collision is to brake the vehicle and/or ease off the throttle. But, although turning off the throttle is an effective way to deal with an impending collision situation with some other types of vehicles such as, for example, an automobile, such a natural and automatic reaction to an impending collision to a user of a jet-powered watercraft eliminates the steering capability of the watercraft. This consequently puts the user in a situation in which he has no control over the direction of movement of the watercraft. Thus, turning off the throttle to avert a collision with a dock, swimmer, shore line etc. makes a collision more likely.
Typical jet-powered watercraft hull designs provide relatively low hydrodynamic drag. Consequently, when the throttle is shut off, the inertia of the watercraft can allow the watercraft to continue to move through the water for a long time and for a long distance. Thus, the watercraft can move for a long time and long distance and sometimes at a high speed without the user being able to steer the watercraft. Collisions with other persons and obstacles in the water are not uncommon.
Some prior art designs have addressed these dangers presented by watercraft design by providing add-on rudders to the watercraft. Some of these designs have positioned the rudders behind the main body of the watercraft. Although such placement provides reasonably effective steering capability, it also adds a structure which is not readily visible and extending out from the main body and thus likely to present an obstacle. Thus, some such designs are deemed hazardous and have been banned. Similarly, some rudder designs which fix the rudders below the main body of the watercraft are also deemed hazardous and have been banned.
Some prior art auxiliary steering mechanisms have positioned a rudder below the nozzle of the engine. The rudder is spring biased which allows the rudder to move up when it strikes something in the water. Although such auxiliary steering mechanisms provide a desired degree of steering capability to the watercraft they also introduce a significant amount of drag which is always present whether or not the engine is on and producing thrust. The rudder also presents lateral drag preventing lateral movement or skimming of the watercraft over the water surface. By compromising the skimming feature, such rudder mechanisms tend to make the watercraft more likely to capsize.
Conventional personal watercraft in which the user sits upright have a high center of gravity which makes them prone to capsizing. They also have lower maneuverability in comparison to personal watercraft in which the user lies prone thereon. Consequently, such watercraft are relatively more hazardous when the engine is off particularly in rough waters.
Recognizing the dangers of such personal watercraft, some prior art accessories for such watercraft have been designed which provide steering capabilities thereto in the event the engine is off. One such type of design is disclosed in U.S. Pat. No. 6,086,437 to Murray. The Murray invention is a rudder, cap and steering linkage assembly which mounts onto the nozzle end of a jet ski engine. A spring pulls the rudder down so that it is below and behind the jet ski main body. In this position, the rudder effectively steers the craft when actuated by steering linkage which laterally rotates the entire nozzle end assembly. Murray's invention utilizes a cap which covers the nozzle outlet. The jet stream force impinging on the cap when the engine is operative pushes the cap and rudder connected thereto up and out of the water environment and into the jet stream where it is relatively ineffective in steering the watercraft. The Murray invention effectively addresses the inherent dangers of jet-powered watercraft which rely on engine operation to steer the watercraft. However, the Murray design disadvantageously adds excessive bulk to the watercraft. In addition, this bulk is below and behind the watercraft and thus positioned where it is likely to hit or get hit by someone or something. Consequently, such designs present new hazards.
Other types of jet-powered watercraft accessories utilize the jet stream force to actuate a retractable rudder. Such an accessory is disclosed in U.S. Pat. No. 6,302,047 to Cannon. As with the Murray assembly, the Cannon assembly provides steering capability only when the throttle is in the off position or when the engine is off. The Cannon rudder is mounted on a rotatable shaft positioned in the exhaust nozzle. In one embodiment the rudder is positioned next to the nozzle while in another embodiment the rudder is positioned below the nozzle. However, as with the Murray design, the Cannon design positions the rudder away from the main body of the watercraft where it can likely hit or get hit by someone or something in the water. Consequently, although the Cannon design resolves some dangers in operation of jet-powered watercraft, it introduces new dangers as well.
Some designers of jet skis have sought to improve the safety of such watercraft by providing brakes thereon. An example of such a jet ski design is disclosed in U.S. Pat. No. 5,092,260 to Mardikian. The Mardikian patent illustrates a rotatable braking structure which is positioned underneath the hull of the craft. The braking structure is basically a flap mounted on the undersurface of the hull which is manually operated. When manually rotated into position, the flap deflects water to produce the braking effect. However, this design introduces lateral drag to the craft that may detract from its desirable lateral skimming features thereby making it more likely to capsize under some circumstances. The Mardikian patent also shows another embodiment featuring braking pads on the rotating shaft of the engine. This uses reduction of engine propulsion to produce a braking effect. This invention thus effectively improves the safety of the jet ski design. Nevertheless, steering capability is still needed before the braking systems can bring the watercraft to a complete stop.
What is therefore needed is an add-on steering component accessory for a jet-powered watercraft which enables steering thereof in engine off or throttle off conditions for improved safe use thereof. What is also needed is an improved steering component accessory for a jet-powered watercraft which does not compromise the hydrodynamic attributes of the watercraft. Such an improved steering component accessory is needed which does not detract from the smooth structure and compact size and shape of the watercraft so as not to present an obstacle in use of the watercraft.